A commenter took exception to my assertion that the practical effect of this is to empty these concepts of any meaning. She said that though these relationships - gay unions, etc. - might seem meaningless to me, they are meaningful to the people involved. To this, I replied;
I never said that the relationships were meaningless, I said that this approach makes the word "family" meaningless. It becomes a word with no content, signifying nothing. The same goes for "marriage" that includes any number of consenting adults of either sex, as long as they feel a certain way... for now.
Any word that I, or anyone, can define however they like is a meaningless word. We could substitute a nonsense word - say, "sniglet" - and get on just as well.
But the word family has always had a particular meaning, and still does. Primarily, it means one's "blood relations".
I love the ad-hoc nature of families, the fact that we (for the most part) don't get to pick our family members. We either learn to get along - to accept and love these people as they are, warts and all - or we have a very hard time in life. The family is our first classroom, where we should learn to get along with other people, even the one's we find irritating.
The average peasant has understood forever what the egg-headed social engineers have forgotten... that "Mom, Dad & Kids" ought to be specially encouraged and preferred to other arrangements.
Does that mean that adoptive families, or childless families don't count? Of course not. But when we begin, as a culture, to discourage having children (the population controllers) or to promote and normalize childless family arrangements, that does damage to society. Western nations are actually shrinking, on the whole... committing cultural suicide. We apparently don't care that much whether life goes on, or not, so long as we can retire comfortably.
There is a saying that goes "Babies are God's way of saying that the world should go on". Our current attitude toward babies, then, says that the world going on doesn't much matter to us one way or another. "Life? Eh..."
I'm not saying that I prefer traditional marriage just out of utilitarian concerns. There is a great deal more to it than that. But there are practical consequences to ignoring the way God made things, even if everything might seem hunky-dory in this or that individual case.
The reverse is also true. Contentious, unhappy marriages aren't caused by the institution of marriage, they are caused by the same things that cause all contentious and unhappy relationships... selfishness, pride, that kind of thing.
People don't even need to be especially compatible to be happily married. They only need to have learned ordinary respect. The three most important words in any marriage are not "I love you", but "please" and "thank you".